Disabled CMEK Versions: Trace the Dependent Service

A customer-managed encryption key adds an explicit availability dependency between a resource and Cloud KMS. When the relevant key version is disabled, data requiring that version cannot be decrypted through the normal supported path. The resource's own IAM policy and the key's IAM policy are separate, so a user may have permission to view a resource while its service agent cannot decrypt it.

CMEK-integrated services perform encryption operations through documented service agents. Giving an end user decryption permission does not necessarily repair the service agent's missing access. Likewise, selecting a newer primary key version does not make older encrypted data independent of the version that protected it. Diagnose the exact resource and version before changing key state.

Prepare the affected resource identifier, encryption configuration, KMS project and location, key owner, and change history. Obtain read access to key metadata and relevant service logs. Do not disable, destroy, or rotate additional versions to test a production outage. Use an isolated resource for planned key-revocation exercises.

1. Read the resource's encryption metadata using its service-specific describe operation. Identify the configured key and, where exposed, the version associated with the failing data. Avoid assuming the current primary version is the only version in use.
2. Inspect gcloud kms keys versions list --key=KEY_NAME --keyring=KEYRING --location=LOCATION --project=KEY_PROJECT. Check version state and recent administrative events. Distinguish disabled, scheduled-for-destruction, and other states because their supported recovery procedures differ.
3. Read key IAM policy and identify the documented service agent for the dependent service. Confirm its encryption and decryption permission on the appropriate key. Review whether the resource project, key project, or service identity changed during a migration.
4. Have the authorized key owner apply the justified recovery action. If re-enabling a version, follow the current KMS and dependent-service documentation. Observe the resource's own recovery state; different services can have additional detection, retry, or restart behavior beyond the KMS operation itself.

A fictional storage-backed processing service loses access after an operator disables an older key version, assuming a newer primary has replaced it everywhere. The object metadata and key history show that older content still depends on the disabled version. The approved recovery restores that version and verifies the service agent's access. The team then creates a separate, tested plan for any desired re-encryption rather than treating rotation as retroactive migration.

Read a harmless representative resource through the ordinary application path. Include old and recently created encrypted data when relevant. Confirm the service agent and resource remain within intended permissions. Review application errors and queued work after access returns, and reconcile operations that failed during the outage. A successful KMS describe call does not establish restored application availability.

Maintain a key-to-service dependency inventory with owners and recovery instructions. Review old-version usage before any disable or destruction action. Monitor KMS access denials, key-state changes, and dependent-service health together. Rehearse revocation and recovery using isolated test resources so the team understands the actual service's behavior and operational timing.

Explore Clouvenix cloud security for implementation and operational handover.

Technical reference

version enable and disable and CMEK service integration.